You have your facts mixed up.
We KNOW why that developer was fired. He told us why he was fired on these forums. He publicly said some disparaging remarks about the Blizzard development team, and he was let go. It had little to do with the design of the Warlock class going into MoP.
Additionally, the notion that MoP's Warlock design was just a gigantic mistake constructed by a crazed lone developer is FALSE. Its a known fact that any major class design change at Blizzard is done via committee, and GC is a part of that. So any major changes that took place to Demonology in this expansion was AGREED UPON by the entire Warlock design team, not that single developer who got fired.
Blizzard pulled back on the glyph because they didn't want Warlocks to be able to tank by switching glyphs. The glyph itself remained in the game, and has been getting tweaks throughout the expansion. Furthermore, the glyph isn't the main thing that links Demonology to Demon Hunters. Metamorphosis and Demonic Fury is the main thing that kills any hope of a Demon Hunter class, and its an integral part of the Demonology spec. The model for Metamorphosis is Illidan. Via Metamorphosis you get Immolation Aura. You build up demonic fury and transform into a demon for several seconds, unleashing enhanced demonic attacks. That's exactly how most people would envision a DH resource system to work, and Warlocks have it.
Also there was the Betrayer Armor, which was armor linked directly to Illidan, and we had the beta Warlock talent "Illidan's Guile", which was pulled before the end of beta, but has a good chance of turning up again in the future.
I find it the height of hypocrisy that you ignore all of this evidence, yet you try to link up Engineering with a possible technology class on the flimsiest of connections.